Abstract: An article and method of forming the article are disclosed. The article has a surface comprising a duplex nanostructured ferritic alloy. The surface includes a plurality of nanofeatures that include complex oxides of yttrium and titanium disposed in an iron-bearing alloy matrix. The iron-bearing alloy matrix includes both a ferrite phase and an austenite phase. Further, a concentration of a chi phase or a sigma phase in the duplex nanostructured ferritic alloy at the surface is less than about 5 volume percent. The method generally includes the steps of milling, thermo-mechanically consolidating, annealing, and then cooling at a rate that hinders the formation of chi and sigma phases in the duplex nanostructured ferritic alloy at the surface.

Abstract: A method of forming an article including a nanostructured ferritic alloy is provided. The method provides steps for substantially inhibiting grain growth of a workpiece that includes nanostructured ferritic alloy, during heating and deforming at high temperatures and at high strain rates. Advantageously, the article is formed via conventional high strain rate techniques and thus, cost savings are provided. Articles are also provided which are formed by the method, and the articles so produced exhibit good mechanical properties at high operating temperatures, and thus are utilized as turbomachinery components, and in particular, component of a heavy duty gas turbine or steam turbine. A turbomachinery component comprising an NFA is provided.

Abstract: An article and method of forming the article are disclosed. The article has a surface comprising a nanostructured ferritic alloy. The surface includes a plurality of nanofeatures that include complex oxides of yttrium and titanium disposed in an iron-bearing alloy matrix. The iron-bearing alloy matrix at the surface includes about 5 weight percent to about 30 weight percent of chromium, and about 0.1 weight percent to about 10 weight percent of molybdenum. Further, a concentration of a chi phase or a sigma phase in the nanostructured ferritic alloy at the surface is less than about 5 volume percent. The method generally includes the steps of milling, thermo-mechanically consolidating, annealing, and then cooling at a rate that hinders the formation of chi and sigma phases in the nanostructured ferritic alloy at the surface.

Abstract: A system for mechanical milling and a method of mechanical milling are disclosed. The system includes a container, a feedstock, and milling media. The container encloses a processing volume. The feedstock and the milling media are disposed in the processing volume of the container. The feedstock includes metal or alloy powder and a ceramic compound. The feedstock is mechanically milled in the processing volume using metallic milling media that includes a surface portion that has a carbon content less than about 0.4 weight percent.